I "discovered" port wine a couple of years ago and have mostly bought and drunk tawnys and colheitas (I've only recently expanded my interest to vintage ports, but thats another story)

Due to a trip to Porto last summer and a recent shopping frenzy I'm sitting on about 25 bottles of colheitas an aged tawnys. Since i dont have that many friends who enjoy port, it will take me a few years to finnish them all (and new bottles will be coming in). My question is, for how long can I store them without the port starting to detoriate?

I'm a bit confused since there seem to be many different opinions about it. I asked the question in a wine shop in Porto, who told me that Colheitas (specificly a Noval Colheita) should be consumed within two years from the bottling date. Another wine shop told me tawnys will be good for a couple of decades, while I read in recent review of the Niepoort 30 year old tawny that it will be perfectly drinkable trough 2050.

I know theres a lot of variables at play here, but is it a general rule? I store my bottles sideways in a wine refrigator. I know t-corks should be stored upright, but I have never experiened any leakage.

You're asking a question which is one that is a great topic of discussion amongst Port lovers.

The simple answer is that if you're storing the bottles properly (and it sounds like you are) then drinking them in 30 years time will still bring great pleasure. You can tell this simply by looking at some of our tasting notes such as the one on a bottle of Fonseca 10 Year Old Tawny bottled in 1979 which was opened in 2009 or this bottle of Taylor 20 Year Old Tawny bottled in 1979 which was opened in 2011.

So then there is the question of whether you should keep the bottles or whether you should buy colheita / tawny port for consumption. My opinion is that you should look to the wine maker for guidance to the correct answer. The wine maker will know whether they are blending and bottling a wine which will improve with bottle age or whether they are best when bottled. I don't know any wine makers who say that their Tawnies are best allowed to mature and my experience is that newly bottled Tawnies are fresh and lively whereas Tawnies that have been in the bottle for 30 years have lost all their liveliness but have developed a thickness and smoothness that is missing from the wines which have spent less time in the bottle.

If you keep an eye on eBay and physical auctions it's quite easy and quite cheap to buy Tawny ports which were bottled many years ago. It might be an interesting experiment for you to try an aged Tawny against a fresh Tawny from the same house and experience the difference for yourself. (If you do this, please do share your thoughts with us. It will be very interesting to hear from someone who does this direct comparison - I don't think anyone else on this website has tried this experiment before.)

On the other hand, there are some wine makers who say that their colheita ports do improve with some time in the bottle. Dirk Niepoort is one of those people so don't rush to open and drink your Niepoort colheitas. I'm not sure of any other wine makers who deliberately make or blend their colheita ports to age in the bottle, but perhaps others on the Forum can share the names of producers I have forgotten.

AHB's advice is, as usual, right on target. The answer varies by producer.

A very broad and general rule of thumb is that tawnies and Colheitas should be consumed within 3-5 years of bottling. I have many in my cellar older than that, though, because as AHB explained the extra age simply changes them. It doesn't mean they're going bad. I happen to like the way they change, so for me 8-12 years in bottle seems like the prime drinking window.

Boy you sure asked the hornets nest of a question, lots of varying answers to this one.

AHB's answer is pretty spot on. I will add most producers say it's best to consume them within 2-4 (or so) years of bottling. Of course even this can vary depending on what it is that is bottled. Example, perhaps Company X puts out a 1930 and a 2005 Colheita. They may say the 1930 should drunk withing a few years but the 2001 is good up to 10 years.

Niepoort is probably one of the few that generally says their Colheita's can and will age over time after being bottled. They tend to the exception and not the rule.

Generally, and unless something goes really wrong, Colheita's won't go bad per se they simply change. They may lose their "freshness" and perceived acidity (becomes overtly sweet/sugary tasting), the flavors may become muted, etc. Some hold up better than others over time. That's why you'll see notes on some of those old ones that are still positive. Of course, one thing that is often overlooked by people who taste those long ago bottled Colheita's is how they were bottled. Now days there is far more fining, filtrating, and cold stabilizing of Ports so they stay "shelf stable" while being shipped around the world and as they sit on store shelves. While in the past things tended to have less of that. So a modern release may not age as well as a much earlier release of it.

I would also day that it depends on you and your tastes. Generally speaking, I am not a huge fan of long ago bottled Tawny's as most of them become flat to me. Especially ones that have become very cloudy in appearance when that very fine stirred up sediment alters the taste of it, making it seem even more flat. Though I have had some that were fantastic as well. So it will also come down to your taste preferences, we're all different.

I realise these are complex questions with many different answers, but it seems that I'm good to go as most of my bottles will be consumed within five years or less.

I agree that ideally I should buy colheitas and tawnys for consumption instead of keeping the bottles, but I live in Norway where the selection of port wine is limitided and import of alcohol is restricted and subject to taxes. I could order bottles from foreign wine shops, but it's a complex and rather expensive process just for a bottle or three. This means that I have to buy interesting bottles when they are avaiable or stock up when I'm traveling, thus leaving me in a situation where I have to keep bottles for a while.

I will look into buying an older bottle of tawny to compare with a new one, as it would be an interesting experiment. But as mentioned importing alcohol is expensive, so I'm probably better off buying a bottle if I find my self in Porto again (which I'm planning on sometime this year). Any recommendation for shop in Porto who might stock older bottles of tawnys?